She’s out there too, in this reality. She’s still alive.

As soon as the thought enters my head, I’m up and out of my chair, mumbling an excuse to Alice behind me. My heart is thudding in my chest; I’m suddenly desperate to hear her voice. I step out into the freezing cold and press my phone against my ear, thinking: please, please, please pick up …

‘Hello, darling!’ she trills. ‘Merry Christmas!’

The winking Christmas lights on the lamp posts begin to dissolve in front of me as the tears blur my vision. I have to bite the inside of my cheek hard to keep it together. ‘Hi, Mum, merry Christmas!’ I’m trying to keep my voice steady, but I’m not totally sure I’m succeeding.

‘I was going to call you later, when I got back from Simon’s,’ she says. ‘Is this costing you an absolute fortune? I can call you back if you want?’

‘No, no, don’t worry.’ God, it is so good to hear her voice. She sounds happy – and more than a little tipsy – and I’m suddenly overwhelmed with gratitude for this chance to speak to her again.

‘I just wanted to say that I miss you,’ I mumble. ‘I wish I was there with you.’

She drops her voice to a whisper. ‘Trust me, you don’t. I spent the whole of lunch sitting next to your cousin Lucy’s incredibly dull new boyfriend. The man talked about nothing but Top Gear for an hour and a half. I am now the world’s leading expert on Richard Hammond. I think I know more about Richard Hammond than Richard Hammond does.’

I am half laughing and half crying now, receiving some very concerned looks from people walking past.

‘So, what are you up to?’ she asks. ‘Please tell me you’re not moping about on your own?’

I take a deep breath and try to pull myself together. ‘No, don’t worry. I’m spending the day with a friend, actually.’

‘Oh, that’s nice. Where do you know him from?’

‘Her, actually. She’s an old friend from uni.’

‘Oh. Right.’ There’s a pause on the other end of the line. And then I hear Mum clear her throat stiffly. ‘And have you heard from Daphne today?’

‘Yeah. Well, I got a Christmas card from her yesterday.’

‘Yes, I got one, too.’ There’s another pause, and she adds, ‘She’s such a lovely girl, honestly.’ I can feel the prickle in her voice.

‘I know,’ I say.

‘I hope you do. You bloody should.’

I was never totally honest with Mum about why Daff and I were taking this break. I just told her it was because Daff was going to New York; I didn’t mention anything about my marriage freak-out; it was way too closely intertwined with her and Dad.